A/c-Heater System - Automatic: Other Toyota Avalon XX10 рестайлинг

SYSTEM CONTROLS

A/C-heater functions are controlled by A/C on-off button, air intake select button, temperature control knob, AUTO button, OFF button, and mode select buttons. A/C-heater controls allow for various selections of air intake source (fresh or recirculated air), air discharge mode, temperature, and blower speed. (Scheme 4)

Air Intake Select Button

Allows fresh or recirculated air intake selection.

A/C On-Off Button

Turns A/C system on and off by signalling A/C amplifier to turn compressor clutch on or off.

Temperature Control Knob

Operates a blend air door which mixes cooled and heated air to obtain desired temperature.

Mode Select Buttons

Directs airflow to desired air outlets.

AUTO Button

Allows system to operate in automatic mode. System automatically selects most suitable fan speed and airflow based on current temperature. Manual control of selected feature(s) is possible while in automatic mode. To cancel automatic operation of a particular feature, press appropriate control button.

OFF Button

Cancels automatic operation of system.

Blower Speed Control Buttons

Allows various selections of blower motor speed.

Scheme 4

A/C Amplifier

A/C amplifier receives signals from various sensors and input devices to determine system operating conditions. When A/C button is in the ON position, A/C amplifier will ground compressor clutch relay to engage compressor clutch, activating compressor.

Air Inlet Servomotor

Servomotor controls a damper door which selects either fresh air or recirculated air for cooling or heating.

Air Mix Servomotor

Servomotor controls damper door positions. Door positions determine amount of air flowing through heater core.

Air Outlet Servomotor

Servomotor controls a damper door which directs air to desired outlet.

Evaporator Temperature Sensor

This sensor is a thermistor located in front of evaporator (air outlet side) and monitors airflow temperature. Sensor is used to prevent evaporator from freezing up. The amplifier processes information from this sensor to send signals to the compressor clutch for on-off cycling.

Pressure Switch

Switch is located in liquid line, on the receiver-drier. Switch monitors system pressure and sends signal to A/C amplifier to control compressor operation. Switch also controls condenser cooling fan operation.

A/C SYSTEM DOES NOT OPERATE

Check A/C fuse and A/C amplifier.

BLINKING A/C INDICATOR

Check compressor, compressor drive belt, compressor lock sensor and A/C amplifier.

DISCHARGE AIR WARMER OR COOLER THAN SET TEMPERATURE

Check refrigerant volume and pressures. Check engine coolant volume. Check compressor drive belt and condenser cooling fan. Check ambient temperature sensor, evaporator temperature sensor and solar sensor. Check air mix servomotor, compressor, condenser, receiver-drier, evaporator and heater core. Check expansion valve A/C amplifier, lower A/C-heater control unit and wire harness/connectors.

INSUFFICIENT AIR OUTPUT

Check blower motor.

NO AIR INLET CONTROL

Check air inlet servomotor, upper A/C-heater control unit, A/C amplifier and wire harness/connectors.

NO AIR TEMPERATURE CONTROL

Check air mix servomotor and lower A/C-heater control unit.

NO BLOWER CONTROL

Check blower motor, blower motor linear controller, A/C amplifier, lower A/C-heater control unit and wiring harness/connectors.

NO COOL AIR

Check refrigerant volume and pressures. Check drive belt, compressor lock sensor and compressor. Check pressure switch, air mix servomotor, room temperature sensor, ambient temperature sensor, lower A/C-heater control unit, A/C amplifier and wire harness/connectors.

NO ENGINE IDLE-UP WITH A/C ON

Check A/C amplifier, idle control system and wire harness/connectors.

NO MODE CONTROL

Check air outlet servomotor, lower A/C-heater control unit, A/C amplifier and wire harness/connectors.

NO WARM AIR

Check engine coolant volume. Check air mix servomotor, room temperature sensor, ambient temperature sensor, A/C amplifier, lower A/C-heater control unit, water valve and heater core.

PANEL BRIGHTNESS DOESN'T CHANGE

Check headlight/tail light systems and A/C-heater control units (upper and lower).

SET TEMPERATURE DOES NOT MATCH TEMPERATURE CONTROL KNOB

Check lower A/C-heater control unit.

A/C SYSTEM PERFORMANCE

Monitor system performance with air inlet temperature at 86-95°F (30-35°C). Connect A/C manifold gauge set. Run engine at 1500 RPM. Set blower to high speed. Set temperature control for maximum cooling. Set outlet airflow to recirculated mode. Ensure that the low-side and high-side pressures are within specifications. See A/C SYSTEM SPECIFICATIONS table at beginning of article.

Scheme 5

1. Remove A/C amplifier located behind lower A/C-heater control unit. See «A/C-HEATER UNIT»(ref-36695-S05687159072001010900000) under REMOVAL & INSTALLATION. Disconnect specified amplifier connector and inspect between specified terminals of that harness connector. (Scheme 5) Turn ignition switch on. Turn A/C switch on.
2. Check continuity between ground and terminal A1 of A/C amplifier harness connector. (Scheme 5) If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
3. Check continuity between ground and terminal A6 of A/C amplifier harness connector. If continuity is not present, go to next step. If continuity is present, repair appropriate wire and retest.
4. Check continuity between terminals A18 and C2 of A/C amplifier harness connector. With solar sensor covered with cloth, continuity should be present. With light shining on solar sensor, continuity should not be present. If continuity is as specified, go to next step. If continuity is not as specified, repair appropriate wire or sensor and retest. See «SENSORS»(ref-36695-S23332417752001010900000).
5. Check continuity between ground and terminal C13 of A/C amplifier harness connector. Push in OFF switch on lower A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
6. Check continuity between ground and terminal C14 of A/C amplifier harness connector. Push in LO switch on lower A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
7. Check continuity between ground and terminal C15 of A/C amplifier harness connector. Push in medium/low blower switch on lower A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
8. Check continuity between ground and terminal C16 of A/C amplifier harness connector. Push in medium/high blower switch on lower A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
9. Check continuity between ground and terminal C17 of A/C amplifier harness connector. Push in HI switch on lower A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
10. Check continuity between ground and terminal C18 of A/C amplifier harness connector. Push in AUTO switch on lower A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
11. Check continuity between ground and terminal C20 of A/C amplifier harness connector. Push in defrost switch on lower A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
12. Check continuity between ground and terminal C21 of A/C amplifier harness connector. Push in air intake select switch on upper A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
13. Check continuity between ground and terminal C22 of A/C amplifier harness connector. Push in A/C switch on upper A/C-heater control unit. If continuity is present, go to next step. If continuity is not present, repair appropriate wire and retest.
14. Check resistance between terminals B1 and A9 of A/C amplifier harness connector. Resistance should be 165-205 ohms at 77°F (25°C). If resistance is as specified, go to next step. If resistance is not as specified, repair appropriate wire and retest.
15. Check resistance between terminals C6 and A9 of A/C amplifier harness connector. Resistance should be about 1700 ohms at 77°F (25°C). If resistance is as specified, go to next step. If resistance is not as specified, repair appropriate wire and retest.
16. Check resistance between terminals C7 and A9 of A/C amplifier harness connector. Resistance should be about 1700 ohms at 77°F (25°C). If resistance is as specified, go to next step. If resistance is not as specified, repair appropriate wire and retest.
17. Check resistance between terminals C8 and A9 of A/C amplifier harness connector. Resistance should be about 1500 ohms with evaporator temperature at 77°F (25°C). If resistance is as specified, go to next step. If resistance is not as specified, repair appropriate wire or sensor and retest. See «SENSORS»(ref-36695-S23332417752001010900000).
18. Check voltage between ground and terminal A3 of A/C amplifier harness connector. Battery voltage should be present with ignition switch in RUN position. No voltage should be present with ignition switch in LOCK or ACC position. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or sensor and retest.
19. Check voltage between ground and terminal No. 20 of A/C amplifier harness connector. Battery voltage should exist at all times. If voltages and values specified in all previous tests are correct, temporarily substitute a known good amplifier and retest. If voltage is not as specified, repair appropriate wire and retest.

A/C AMPLIFIER VOLTAGE CHECKS

Note. Make all measurements by backprobing wire side of the A/C amplifier harness connector.

1. Remove A/C amplifier located behind lower A/C-heater control unit. See REMOVAL & INSTALLATION in «A/C-HEATER SYSTEM - MANUAL»(ref-36697) article. Leave A/C amplifier harness connectors connected. Start engine and allow to idle.
2. Check voltage between ground and terminal A3 of A/C amplifier harness connector. (Scheme 5) With compressor clutch engaged, voltage should be less than one volt. With compressor clutch not engaged, voltage should be 10-14 volts. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
3. Check voltage between ground and terminal A12 of A/C amplifier harness connector. Recirculate indicator light should illuminate within 16 seconds and battery voltage should be present. If indicator and voltage is as specified, go to next step. If indicator and voltage is not as specified, repair appropriate wire or circuit and retest.
4. Check voltage between ground and terminal A13 of A/C amplifier harness connector. Fresh air indicator light should illuminate within 16 seconds and battery voltage should be present. If indicator and voltage is as specified, go to next step. If indicator and voltage is not as specified, repair appropriate wire or circuit and retest.
5. Check voltage between ground and terminal A14 of A/C amplifier harness connector. Turn temperature control knob to maximum warm. Battery voltage should be present. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
6. Check voltage between ground and terminal A15 of A/C amplifier harness connector. Turn temperature control knob to maximum cool. Battery voltage should be present. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
7. Check voltage between ground and terminal A16 of A/C amplifier harness connector. Operate blower motor. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
8. Check voltage between ground and terminal B2 of A/C amplifier harness connector. Push in AUTO button. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
9. Check voltage between ground and terminal B3 of A/C amplifier harness connector. Push in A/C button. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
10. Check voltage between ground and terminal B5 of A/C amplifier harness connector. Push in face button. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
11. Check voltage between ground and terminal B6 of A/C amplifier harness connector. Push in bi-level button. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
12. Check voltage between ground and terminal B7 of A/C amplifier harness connector. Push in foot button. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
13. Check voltage between ground and terminal B8 of A/C amplifier harness connector. With compressor clutch engaged, voltage should be 10-14 volts. With compressor clutch not engaged, voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
14. Check continuity between ground and terminal B9 of A/C amplifier harness connector. With refrigerant pressure at 28 psi (2.0 kg/cm 2 )-455 psi (32.0 kg/cm 2 ), continuity should exist. With refrigerant pressure less than 28 psi (2.0 kg/cm 2 ) or more than 455 psi (32.0 kg/cm 2 ), continuity should not be present. If continuity is as specified, go to next step. If continuity is not as specified, repair appropriate wire or circuit and retest. If appropriate wire or circuit is okay, test pressure switch. See TESTING in «A/C-HEATER SYSTEM - MANUAL»(ref-36697) article.
15. Check voltage between ground and terminal B10 of A/C amplifier harness connector. Push in defrost button. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
16. Check voltage between ground and terminal B14 of A/C amplifier harness connector. With fresh air intake indicator illuminated, voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
17. Check voltage between ground and terminal B15 of A/C amplifier harness connector. With recirculated air intake indicator illuminated, voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
18. Check voltage between ground and terminal B17 of A/C amplifier harness connector. Push in foot/defrost button. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
19. Check voltage between ground and terminal B18 of A/C amplifier harness connector. Push in defrost button. Voltage should be less than one volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
20. Check voltage between ground and terminal C1 of A/C amplifier harness connector. With engine running, voltage should pulse from less than one volt to battery voltage. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
21. Check voltage between terminals C3 and A9 of A/C amplifier harness connector. Turn temperature control knob to maximum warm position. Voltage should be one volt. Turn temperature control knob to maximum cool position. Voltage should be 4.0 volts. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
22. Check voltage between ground and terminal C4 of A/C amplifier harness connector. Press appropriate blower control button and note voltage. See «AMPLIFIER BLOWER CONTROL VOLTAGE»(ref-36695-S07873108682001010900000) table. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest. AMPLIFIER BLOWER CONTROL VOLTAGE Blower Control Button Approximate Voltage LO 1.15 Medium/Low 2.04 Medium/High 2.95 HI 3.87 AUTO 0.00
23. Check voltage between terminals C5 and A9 of A/C amplifier harness connector. Turn temperature control knob to maximum cool position. Voltage should be 4.7 volts. Turn temperature control knob to 75 degree position. Voltage should be 2.5 volts. Turn temperature control knob to maximum warm position. Voltage should be 0.3 volt. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest.
24. Check voltage between ground and terminal C9 of A/C amplifier harness connector. Press appropriate mode select button and note voltage. See «AMPLIFIER MODE SELECT VOLTAGE»(ref-36695-S34138151892001010900000) table. If voltage is as specified, go to next step. If voltage is not as specified, repair appropriate wire or circuit and retest. AMPLIFIER MODE SELECT VOLTAGE Mode Select Button Approximate Voltage Face Less Than 1.0 Bi-level 1.2 Foot 2.6 Foot/Defrost 3.6 AUTO or Defrost 5.0
25. Check voltage between terminals C11 and A9 of A/C amplifier harness connector. With recirculated air indicator illuminated, voltage should be 4.0 volts. With fresh air indicator illuminated, voltage should be one volt. If voltage is as specified and values specified in all previous tests are correct, temporarily substitute a known good amplifier and retest. If voltage is not as specified, repair appropriate wire or circuit and retest.

BLOWER MOTOR LINEAR CONTROLLER

Disconnect blower motor linear controller connector. Inspect connector for good terminal contact. Connect the connector to blower motor linear controller. Turn ignition on. Operate the blower motor and backprobe between ground and the specified connector terminal. Refer to the BLOWER MOTOR LINEAR CONTROLLER CIRCUIT table. Also (Scheme 6) If values are not as specified, inspect related circuit. See WIRING DIAGRAMS. If values are as specified, replace with a known good unit and retest.

BLOWER MOTOR LINEAR CONTROLLER CIRCUIT

Scheme 6

LOWER A/C-HEATER CONTROL UNIT

1. Remove lower A/C-heater control unit and disconnect connectors. See REMOVAL & INSTALLATION in «A/C-HEATER SYSTEM - MANUAL»(ref-36697) article. Remove A/C amplifier from rear of lower A/C-heater control unit.
2. Using fused jumper wires, apply battery voltage to terminal B14 and ground terminal B6 of lower A/C-heater control unit. (Scheme 7) If control unit panel illuminates, go to next step. If panel does not illuminate, check bulb and replace as necessary. If bulb is okay, replace lower A/C-heater control unit.
3. Apply battery voltage to terminal A7 and ground terminal A1 of lower A/C-heater control unit. Press each mode select button, in turn, and ensure respective button LED indicator comes on. If LED indicator of each button comes on as specified, go to next step. If not, replace lower A/C-heater control unit.
4. Check continuity between indicated terminals while pressing the specified button. See «LOWER A/C-HEATER CONTROL UNIT»(ref-36695-S02230237382001010900000) CONTINUITY table. Continuity should exist between terminals listed when respective button is pushed. If continuity is as specified, go to next step. If continuity is not as specified, replace lower A/C-heater control unit. LOWER A/C-HEATER CONTROL UNIT CONTINUITY Button Pressed Continuity Between Terminals Face B3 & B11 Bi-Level B9 & A1 Foot A14 & A1 Defrost A3 & A1 LO A15 & A1 Medium/Low A13 & A1 Medium/High A12 & A1 HI A9 & A1
5. Apply battery voltage to terminal A7 and ground terminal A1 of lower A/C-heater control unit. (Scheme 7) Press AUTO button, ensure button LED indicator comes on. If LED indicator comes on, go to next step. If not, replace lower A/C-heater control unit.
6. Check continuity between terminals A8 and A1 of lower A/C-heater control unit while pressing AUTO switch. If continuity exists, go to next step. If continuity does not exist, replace lower A/C-heater control unit.
7. Check continuity between terminals B2 and A1 of lower A/C-heater control unit while pressing OFF switch. If continuity exists, go to next step. If continuity does not exist, replace lower A/C-heater control unit.
8. Check resistance between terminals B11 and B5 of lower A/C-heater control unit. Resistance should be approximately 3000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace lower A/C-heater control unit.
9. Check resistance between terminals B4 and B5 of lower A/C-heater control unit. Gradually turn temperature control knob from warm to cool position. Resistance should increase from zero ohms to approximately 3000 ohms as knob is turned. If resistance is as specified, temporarily substitute a known good lower A/C-heater control unit and retest. If resistance is not as specified, replace lower A/C-heater control unit.

Scheme 7

UPPER A/C-HEATER CONTROL UNIT

1. Remove upper A/C-heater control unit and disconnect connectors. See REMOVAL & INSTALLATION in «A/C-HEATER SYSTEM - MANUAL»(ref-36697) article. Using fused jumper wires, apply battery voltage to terminal No. 9 and ground terminal No. 2 of upper A/C-heater control unit. (Scheme 8) If A/C indicator LED illuminates, go to next step. If LED does not illuminate, replace upper A/C-heater control unit.
2. Apply battery voltage to terminal No. 9 and ground terminal No. 14 of upper A/C-heater control unit. If recirculation indicator LED illuminates, go to next step. If LED does not illuminate, replace upper A/C-heater control unit.
3. Apply battery voltage to terminal No. 9 and ground terminal No. 4 of upper A/C-heater control unit. If fresh air indicator LED illuminates, go to next step. If LED does not illuminate, replace upper A/C-heater control unit.
4. With A/C switch on, continuity should exist between upper A/C-heater control unit terminals No. 1 and 11. (Scheme 8) Also, continuity should exist between terminals No. 7 and 8 at all times. If continuity exists between specified terminals, go to next step. If continuity does not exist, replace upper A/C-heater control unit.
5. Apply battery voltage to terminal No. 6 and ground terminals No. 7 and No. 2 of upper A/C-heater control unit. (Scheme 8) With terminal No. 6 still connected to battery voltage, apply battery voltage to terminal No. 8. A/C indicator should dim. If A/C indicator dims, go to next step. If A/C indicator does not dim, replace upper A/C-heater control unit.
6. While depressing air inlet control button, check that continuity exists between terminals No. 3 and No. 11 of upper A/C-heater control unit. If continuity exists, upper A/C-heater control unit is functioning properly at this time. If continuity does not exist, replace upper A/C-heater control unit.

Scheme 8

RELAYS

For Compressor Clutch Relay, Cooling Fan Relay Nos. 1-3 or Heater Main Relay see TESTING in A/C-HEATER SYSTEM - MANUAL article.

Extra-Hi Speed Blower Relay

1. Check that continuity exists between relay terminals No. 3 and 4. (Scheme 9) If continuity does not exist, replace relay. If continuity exists, go to next step.
2. Apply battery voltage between terminals No. 3 and 4. Check for continuity between terminals No. 1 and 2. (Scheme 9) If continuity exists, relay is okay. If continuity does not exist, replace relay.

Scheme 9

Blower Resistor

Remove driver-side trim panel. Disconnect blower resistor connector. Remove screws, then blower resistor. Using an ohmmeter, measure resistance between resistor terminals. Resistance should be 1.8-2.2 ohms. Replace resistor if resistance is not as specified.

Ambient Temperature Sensor

Disconnect sensor connector and remove sensor. Using an ohmmeter, measure resistance between sensor terminals. Resistance should be 1600-1800 ohms with sensor temperature at 77°F (25°C) and 500-700 ohms at 104°F (40°C). Replace sensor if resistance is not as specified.

Compressor Clutch/Lock Sensor

See TESTING in A/C-HEATER SYSTEM - MANUAL article.

1. Disconnect negative battery cable. Remove passenger-side undercover and trim panel. Remove glove box. Disconnect sensor connector. Using an ohmmeter, measure resistance between sensor terminals. Resistance should be 1500 ohms with sensor temperature at 77°F (25 °C). If resistance is not as specified, replace sensor. If resistance is as specified, go to next step.
2. Remove blower unit. See REMOVAL & INSTALLATION in the «A/C-HEATER SYSTEM - MANUAL»(ref-36697) article. Remove sensor screw and sensor. Submerge sensor and thermometer in cold water. Vary water temperature, and measure resistance between connector terminals at various temperatures. As sensor temperature increases, resistance should gradually decrease. Replace sensor if resistance is not as specified. See «EVAPORATOR TEMPERATURE SENSOR RESISTANCE»(ref-36695-S41018708112001010900000) table.

EVAPORATOR TEMPERATURE SENSOR RESISTANCE

Room Temperature Sensor

Remove center panel upper trim cover. Disconnect sensor connector, and remove sensor from aspirator hose. Using an ohmmeter, measure resistance between sensor terminals at several sensor temperatures. See ROOM TEMPERATURE SENSOR RESISTANCE table. Ensure resistance is within specifications. Replace sensor if resistance is not as specified.

ROOM TEMPERATURE SENSOR RESISTANCE

Solar Sensor

Remove instrument panel. See REMOVAL & INSTALLATION in the A/C-HEATER SYSTEM - MANUAL article. Disconnect sensor connector, and remove sensor. Shine light directly onto sensor. Using an ohmmeter, ensure continuity is present between sensor terminals. Completely cover sensor with cloth. Ensure continuity is no longer present between sensor terminals. Replace sensor if continuity is not as specified.

ECT Switch No. 1

Remove ECT switch No. 1. (Scheme 10) Using an ohmmeter, measure resistance between switch terminals at specified temperatures. See ECT SWITCH NO. 1 RESISTANCE table.

ECT SWITCH NO. 1 RESISTANCE

ECT Switch No. 2

Remove ECT switch No. 2. (Scheme 10) Using an ohmmeter, measure resistance between switch terminals at specified temperatures. See ECT SWITCH NO. 2 RESISTANCE table.

ECT SWITCH NO. 2 RESISTANCE

Scheme 10

1. Remove air inlet servomotor. See «SERVOMOTORS REMOVAL & INSTALLATION»(ref-36695-S24875155152001010900000). Using fused jumper wires, apply battery voltage to terminal No. 6, and ground terminal No. 7 of servomotor. (Scheme 11) Servomotor arm should move to fresh position.
2. Remove fused jumper wires. Connect battery voltage to terminal No. 7 and ground terminal No. 6. (Scheme 11) Servomotor arm should move to recirculated air position. Replace servomotor if operation is not as specified.

Scheme 11

1. Remove air mix servomotor. See «SERVOMOTORS REMOVAL & INSTALLATION»(ref-36695-S24875155152001010900000). Disconnect water valve control cable. Using fused jumper wires, apply battery voltage to terminal No. 1, and ground terminal No. 2 of servomotor. (Scheme 12) Ensure servomotor arm moves smoothly to cool position.
2. Reverse battery polarity between terminals No. 1 and 2 of servomotor. (Scheme 12) Ensure servomotor arm moves smoothly to warm position. Replace servomotor if it does not function as specified. If operation is okay, go to next step.
3. Using an ohmmeter, measure resistance between indicated servomotor terminals. See the «SERVOMOTOR RESISTANCE TEST»(ref-36695-S26245242032001010900000) table. Also (Scheme 12) Replace servomotor if resistance is not as specified.

SERVOMOTOR RESISTANCE TEST

Scheme 12

Remove air outlet servomotor. See SERVOMOTORS REMOVAL & INSTALLATION. Apply positive battery voltage to terminal No. 2 and ground terminal No. 1. (Scheme 13) Connect another jumper wire between negative battery terminal and indicated servomotor terminal.

See AIR OUTLET SERVOMOTOR OPERATION TEST table. Servomotor arm should move smoothly to appropriate position. If operation is not as specified, replace servomotor.

AIR OUTLET SERVOMOTOR OPERATION TEST

Scheme 13